Over 230,000 new cases of prostate cancer were diagnosed in the United States in 2005, with over 750,000 men subjected to needle biopsy of the prostate. The growing number of biopsy cores obtained in these patients has resulted in a rapid escalation of costs associated with biopsy and pathological interpretation. The cost and morbidity of this process could be improved by an accurate non-invasive diagnostic test. Clinically significant prostate cancer demonstrates increased neovascularity. Although these microvessels are below the resolution of clinical ultrasound systems, they can be visualized with contrast-enhanced ultrasound. Unfortunately, contrast-enhanced imaging of the prostate lacks specificity due to enhancement of benign prostate tissue. Preliminary studies suggest that short term therapy with Dutasteride, a type l/ll 5- alpha reductase inhibitor approved for treatment of symptomatic BPH, can selectively reduce contrast enhancement associated with benign prostatic tissue. The objective of this study is to improve the detection of clinically significant prostate cancer with targeted biopsy based upon contrast-enhanced ultrasound after short-term dutasteride therapy. Utilizing a double- blinded, randomized study design, 450 subjects with suspected cancer of the prostate will be randomized to pretreatment with dutasteride or placebo for 2 weeks prior to contrast-enhanced, ultrasound guided biopsy of the prostate. A set of targeted biopsy specimens will be obtained from each subject, including up to 6 targeted cores from regions of maximum contrast enhancement. A second, independent set of twelve systematic biopsy specimens will be obtained based upon a spatially distributed conventional biopsy approach. The diagnostic yield of the smaller number of targeted cores will be compared to the larger number of systematic biopsy cores in the treatment and control groups. Based upon preliminary data, we expect that areas of cancer within the prostate will be identified by contrast enhanced ultrasound. A targeted biopsy approach based upon contrast enhanced ultrasound after short term therapy with dutasteride is expected to improve the detection of prostate cancer, reduce the number of negative biopsy cores and provide a cost-effective approach to the diagnosis of prostate cancer. [unreadable] [unreadable] [unreadable]